15.1 Completion

Org has in-buffer completions. Unlike minibuffer completions, which are
useful for quick command interactions, Org's in-buffer completions are more
suitable for content creation in Org documents. Type one or more letters and
invoke the hot key to complete the text in-place. Depending on the context
and the keys, Org will offer different types of completions. No minibuffer
is involved. Such mode-specific hot keys have become an integral part of
Emacs and Org provides several shortcuts.

M-<TAB>

Complete word at point

At the beginning of a headline, complete TODO keywords.

After ‘\’, complete TeX symbols supported by the exporter.

After ‘*’, complete headlines in the current buffer so that they
can be used in search links like ‘[[*find this headline]]’.

After ‘:’ in a headline, complete tags. The list of tags is taken
from the variable org-tag-alist (possibly set through the
‘#+TAGS’ in-buffer option, see Setting tags), or it is created
dynamically from all tags used in the current buffer.

After ‘:’ and not in a headline, complete property keys. The list
of keys is constructed dynamically from all keys used in the current
buffer.